The Japanese word "Zainichi" itself means a foreign citizen "staying in Japan" and implies temporary residence. [4] Nevertheless, the term "Zainichi Korean" is used to describe settled permanent residents of Japan, both those who have retained either their Joseon or South Korean / North Korean nationalities, and even sometimes, but not always, includes Japanese citizens of Korean descent who acquired Japanese nationality by naturalization or by birth from one or both parents who have Japanese citizenship.